Radio controlled timepiece, electronic device and time correction method

Abstract

A clocking unit ( 27 ) that clocks a time; a display unit ( 3 ) that displays a time based on clock information from the clocking unit ( 27 ); a receiving unit ( 20 ) that receives standard radio waves from transmitting stations in at least two countries or regions; a second-synchronization detecting unit ( 23 ) that detects second-synchronization information (P 3 ) from a demodulated signal (P 2 ) obtained by the receiving unit ( 20 ); a transmitting station determining unit ( 25 ) that analyzes the demodulated signal (P 2 ) based on the second-synchronization information (P 3 ) to determine a transmitting station in a country or a region; and a decoding unit ( 26 ) decodes information included in the standard radio wave from the transmitting station determined by the transmitting station determining unit ( 25 ) to obtain time information are included, and the clock information of the clocking unit ( 27 ) is corrected based on the time information obtained by the decoding unit ( 26 ).

1. A radio controlled timepiece comprising:
 a clocking unit configured to clock a time; 
 a display unit configured to display a time based on clock information from the clocking unit; 
 a receiving unit configured to receive standard radio waves from transmitting stations in at least two countries or regions; 
 a second-synchronization detecting unit configured to detect second-synchronization information from a demodulated signal obtained by the receiving unit, wherein the second-synchronization detecting unit includes:
 an edge detecting unit configured to sequentially or synchronously detect rising edges and falling edges of the demodulated signal; and 
 a synchronization determining unit configured to obtain the second-synchronization information of the demodulated signal based on the detected rising edges or the detected falling edges; 
 
 a transmitting station determining unit configured to analyze the demodulated signal based on the second-synchronization information to determine a transmitting station in a country or a region; and 
 a decoding unit configured to decode information included in the standard radio wave from the transmitting station determined by the transmitting station determining unit to obtain time information, wherein 
 the clock information of the clocking unit is corrected based on the time information obtained by the decoding unit. 
 
   
   
     2. The radio controlled timepiece according to  claim 1 , wherein the receiving unit includes a reception switching unit and the reception switching unit is configured to receive a standard radio wave from another transmitting station with the reception switching unit if the second-synchronization information cannot be detected by the second-synchronization detecting unit, if the transmitting station cannot be determined by the transmitting station determining unit, or if the time information cannot be decoded by the decoding unit. 
   
   
     3. The radio controlled timepiece according to  claim 1 , wherein the transmitting station determining unit is configured to analyze the demodulated signal based on the second-synchronization information to determine the transmitting station in the country or region from a waveform of a position marker appearing in a constant cycle. 
   
   
     4. The radio controlled timepiece according to  claim 1 , wherein the transmitting station determining unit is configured to analyze the demodulated signal based on the second-synchronization information to determine the transmitting station in the country or region based on a particular waveform of the demodulated signal. 
   
   
     5. The radio controlled timepiece according to  claim 1 , wherein the second-synchronization detecting unit is configured to prioritize an order in determination of the transmitting station by the transmitting station determining unit based on the detected second-synchronization information. 
   
   
     6. The radio controlled timepiece according to  claim 1 , wherein the receiving unit is configured to receive a standard radio wave of a transmitting station from which a standard radio wave is successfully received in last reception, first. 
   
   
     7. The radio controlled timepiece according to  claim 1 , wherein the receiving unit includes a storing unit configured to store information on a transmitting station for which reception has succeeded before, and is configured to determine an order of switching based on the information on the transmitting station stored in the storing unit. 
   
   
     8. An electronic device comprising the radio controlled timepiece according to  claim 1 . 
   
   
     9. A radio controlled timepiece comprising:
 a clocking unit configured to clock a time; 
 a display unit configured to display a time based on clock information from the clocking unit; 
 a receiving unit configured to receive standard radio waves from transmitting stations in at least two countries or regions; 
 a second-synchronization detecting unit configured to detect second-synchronization information from a demodulated signal obtained by the receiving unit, wherein the second-synchronization detecting unit includes; 
 a sampling unit configured to sequentially or synchronously detect logic “1” or logic “0” of the demodulated signal at regular intervals; and 
 an adding unit configured to add up a number of times of detection of any one of the logic “1” and the logic “0” detected by the sampling unit, 
 a transmitting station determining unit configured to analyze the demodulated signal based on the second-synchronization information to determine a transmitting station in a country or a region; and 
 a decoding unit configured to decode information included in the standard radio wave from the transmitting station determined by the transmitting station determining unit to obtain time information, wherein 
 the clock information of the clocking unit is corrected based on the time information obtained by the decoding unit, and 
 the transmitting station determining unit is configured to determine the transmitting station in the country or region based on a result of addition by the adding unit in the second-synchronization detecting unit. 
 
   
   
     10. A radio controlled timepiece, comprising:
 a clocking unit configured to clock a time; 
 a display unit configured to display a time based on clock information from the clocking unit; 
 a receiving unit configured to receive standard radio waves from transmitting stations in at least two countries or regions; 
 a second-synchronization detecting unit configured to detect second-synchronization information from a demodulated signal obtained by the receiving unit, wherein the second- synchronization detecting unit includes:
 a sampling unit configured to sequentially or synchronously detect rising edges and falling edges of the demodulated signal; and 
 an adding unit configured to add up a number of times of detection of the rising edges and falling edges of the demodulated signal; 
 
 a transmitting station determining unit configured to analyze the demodulated signal based on the second-synchronization information to determine a transmitting station in a country or a region; and 
 a decoding unit configured to decode information included in a standard radio wave from the transmitting station determined by the transmitting station determining unit to obtain time information, wherein 
 the clock information of the clocking unit is corrected based on the time information obtained by the decoding unit. 
 
   
   
     11. The radio controlled timepiece according to  claim 10 , wherein
 the sampling unit is configured to sequentially and synchronously detect the rising edges and falling edges of the demodulated signal at regular intervals, and 
 the adding unit is configured to add up the number of times of detection of the rising edges and the falling edges detected by the sampling unit for each sampling position, and the second-synchronization detecting unit further includes: 
 a storing unit configured to store the number of times of the detection of the rising edges and the falling edges added up for each sampling position by the adding unit; and 
 a waveform determining unit configured to obtain the second-synchronization information of the demodulated signal based on the number of times of the detection of the rising edges and the falling edges for each sampling position stored in the storing unit.